New test predicts spread of kidney tumours

A simple, inexpensive, and reliable test can identify kidney tumours that are most likely to spread to the rest of the body, according to researchers in the July issue of The Lancet Oncology. The test, which identifies tumours that contain the protein IMP3, "could therefore also be used to effectively target individuals who would most likely benefit from additional treatment", says Zhong Jiang, University of Massachusetts, USA.

"Tumour metastasis, the spread of cancerous cells from an original site to elsewhere in the body, is almost always deadly news for cancer patients, whereas a patient with a tumour that does not develop metastasis will be more likely to have a good lifespan after the removal of the original tumour", explains Jiang. "Early detection and treatment of these patients with a high potential to develop metastasis is crucial for the survival of cancer patients", he adds.

As part of their programme to develop biomarkers for clinical use, Jiang and colleagues studied the expression of IMP3 in 501 patients with primary and metastatic renal-cell tumours. They then further studied 371 of these patients who had localised primary tumours to see whether their cancer spread. The researchers found that presence of IMP3 was significantly increased not only in metastatic renal cell tumours but also in primary tumours that later developed metastases: patients with IMP3-positive primary tumours were almost six times more likely to subsequently develop metastasis and four times more likely to die than were those with IMP3 negative tumours, even after adjustment for other well-known clinical variables.

At present, 'watchful waiting' is the standard of care for patients with localised kidney cancers that have been removed by surgery. With use of IMP3, however, patients with early-stage disease and a high potential to develop metastasis after surgery can be identified.